var index = 0;
var imgs = [
	"../img/challenge/top1_3.jpg",
	"../img/challenge/top1_2.jpg",
	"../img/challenge/top1_4.jpg",
	"../img/challenge/top1_5.jpg",
]; /*图片的地址 */
function change() {
	document.getElementById("img_top_one").src = imgs[index];
	index++;
	// alert("jdksajfsdjk")
	if (index > imgs.length - 1) {
		index = 0;
	}
}
setInterval("change()", 3000); 
